My understanding (which may need correction!) is that the conceptof a day of 24 equal length hours is fairly recent (a thousandor so years), except among astronomers. Before that, non astronomersdivided daylight into 12 equal 'hours' and night also into 12 hours,with day and night hours only being equal at the equinoxes.

Does the naming of the weekdays precede or postdate the conceptof a widely accepted 24 hour 'day' which contains both daytimeand nighttime?